Crossifre x8 vs x16 - Performance Difference?

I've done fairly extensive searching, but I can't seem to find any recent, in depth analysis of whether a normal user will notice any real performance boost running a crossfire setup in x16 link vs x8.

I ask because I'm building a new system, and although I'm not planning on going xfire initially, I likely will when the 4850 cards go dirt cheap in the far future, and I'm trying to decide if I need to get:

http://www.newegg.com/Product/Prod [...] 6813128336

or if I should save some $$$ and just go with

http://www.newegg.com/Product/Prod [...] 6813131299

Any info would be greatly appreciated.

Appreciate the reply, but that link is about the results with single cards on various pcie pipeline speeds, not crossfire results.

Here is a review that should answer all your questions.
It has 8 x 8, 16 x 4, 16 x 16. Also PCI 1 vs 2.


http://www.legionhardware.com/document.php?id=761